The following selected transactions were completed by Lindbergh Delivery Service during October:

1. Received cash from owner as additional investment, $75,000.

2. Paid rent for October, $4,200.

3. Paid advertising expense, $4,000.

4. Received cash for providing delivery services, $39,750.

5. Purchased supplies for cash, $2,500.

6. Billed customers for delivery services on account, $81,200.

7. Paid creditors on account, $9,280.

8. Received cash from customers on account, $25,600.

9. Determined that the cost of supplies on hand was $900; therefore, $1,600 of supplies had been used during the month.

10. Paid cash to owner for personal use, $3,000.
Indicate the effect of each transaction on the accounting equation by listing the numbers identifying the transactions, (1) through (10), in a column, and inserting at the right of each number the appropriate letter from the following list:

a. Increase in an asset, decrease in another asset.

b. Increase in an asset, increase in a liability.

c. Increase in an asset, increase in owner's equity.

d. Decrease in an asset, decrease in a liability.

e. Decrease in an asset, decrease in owner's equity.